UD N - Unsave Document - get key Numbers from file

PURPOSE

To find highest key, number of columns, and number of keys used in a document file.

SEE ALSO

UD IC	[Unsave Document - In Core]
UD	[Unsave Document]

USAGE

.OPERATION: UD N [maxkey],[ncols],[nkeys]

[The operation line can specify three optional register variables:

The first (called [maxkey] in this example) receives the maximum key number found in the document file.
The second (called [ncols] in this example receives the number of columns in use in the document file.
The third (called [nkeys] in this example) receives the number of keys in use in the document file.]

.DOCUMENT FILE: DOC555
[Enter the name of an existing document file.]

[In the example let's say the document file has the first 490 keys filled then skips nine keys and fills key number 500 and the maximum number of columns in the document file is 4. The operation listed above will set [maxkey] to: 500, [ncols] to: 4, and [nkeys] to: 491.

NOTES

1. This operation can be slow on large doc files.

2. Works on both file based and incore document files.

SUBROUTINES

RDDOCN, OPENDOC, LUNDOC

CALLER

DRIV3